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-rw-r--r--fs/nilfs2/ioctl.c4
-rw-r--r--fs/nilfs2/super.c3
-rw-r--r--fs/nilfs2/the_nilfs.c1
-rw-r--r--fs/nilfs2/the_nilfs.h2
4 files changed, 8 insertions, 2 deletions
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 06658caa18b..0b6387c67e6 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -182,7 +182,7 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
goto out;
- down_read(&inode->i_sb->s_umount);
+ mutex_lock(&nilfs->ns_snapshot_mount_mutex);
nilfs_transaction_begin(inode->i_sb, &ti, 0);
ret = nilfs_cpfile_change_cpmode(
@@ -192,7 +192,7 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
else
nilfs_transaction_commit(inode->i_sb); /* never fails */
- up_read(&inode->i_sb->s_umount);
+ mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
out:
mnt_drop_write_file(filp);
return ret;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index a76d6ea51ff..6522cac6057 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -945,6 +945,8 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
struct nilfs_root *root;
int ret;
+ mutex_lock(&nilfs->ns_snapshot_mount_mutex);
+
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
up_read(&nilfs->ns_segctor_sem);
@@ -969,6 +971,7 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
ret = nilfs_get_root_dentry(s, root, root_dentry);
nilfs_put_root(root);
out:
+ mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
return ret;
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 501b7f8b739..41e6a04a561 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -76,6 +76,7 @@ struct the_nilfs *alloc_nilfs(struct block_device *bdev)
nilfs->ns_bdev = bdev;
atomic_set(&nilfs->ns_ndirtyblks, 0);
init_rwsem(&nilfs->ns_sem);
+ mutex_init(&nilfs->ns_snapshot_mount_mutex);
INIT_LIST_HEAD(&nilfs->ns_dirty_files);
INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
spin_lock_init(&nilfs->ns_inode_lock);
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index ef40a510e2f..2558f320b82 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -47,6 +47,7 @@ enum {
* @ns_flags: flags
* @ns_bdev: block device
* @ns_sem: semaphore for shared states
+ * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts
* @ns_sbh: buffer heads of on-disk super blocks
* @ns_sbp: pointers to super block data
* @ns_sbwtime: previous write time of super block
@@ -100,6 +101,7 @@ struct the_nilfs {
struct block_device *ns_bdev;
struct rw_semaphore ns_sem;
+ struct mutex ns_snapshot_mount_mutex;
/*
* used for